Sumitomo Electric Industries, Limited

Sumitomo Electric Hardmetal Corp.

Yuichiro Seki

Naoji Fujimori

Keiichiro Tanabe

Hideaki Nakahata

Satoshi Fujii

Shin-ichi Shikata

Tomoki Uemura

Kenjiro Higaki

Akihiko Ikegaya

Kentaro Yoshida

Hiroyuki Kitabayashi

Kiichi Meguro

Katsuhito Yoshida

Shinji Matsukawa

Shigeru Yoshida

Akihoko Ikegaya

Yoshiki Nishibayashi

Hitoshi Sumiya

Akihiko Ueda

Shinichi Shikata

Yutaka Kobayashi

Toshiya Takahashi

Takahiro Imai

Takashi Tsuno

Kenji Izumi

Shin-Ichi Shikata

The diamond coated tool of the present invention is a diamond coated tool including a base material and a diamond layer coating a surface of the base material, and characterized in that the surface of the base material has an arithmetic average roughness Ra of not less than 0.1 &#x3bc;m and not more than 10 &#x3bc;m and an average length of roughness profile elements RSm of not less than 3.1 &#x3bc;m and not more than 5.4 &#x3bc;m, and that the diamond layer has a plurality of cavities at a portion bordering on the base material.

Diamond coated tool

A single crystal diamond () is provided as a single crystal diamond into which a defect portion () is introduced. The defect portion () can be detected by a phase difference occurring when the single crystal diamond () is irradiated with circularly polarized light. In the single crystal diamond (), a maximum value of average values of the phase differences measured within a measurement region (M) formed in a shape of a square having a side length of 1 mm is 30 nm or more.

Single crystal diamond and diamond tool

A single crystal diamond has a surface. In the single crystal diamond, a measurement region is defined in the surface, the measurement region includes a portion exhibiting a transmittance that is highest in the single crystal diamond and a portion exhibiting a transmittance that is lowest in the single crystal diamond, the measurement region has a plurality of square regions that are continuously arranged and each have a side having a length of 0.2 mm, and an average value of transmittances in each of the plurality of square regions is measured, wherein assuming that the average value of the transmittances in one square region is defined as Tand the average value of the transmittances in another square region adjacent to the one square region is defined as T, a relation of ((T&#x2212;T)/((T+T)/2)&#xd7;100)/0.2&#x2264;20 (%/mm) is satisfied throughout the measurement region.

The present invention provides a diamond coated tool which is resistant to exfoliation at an interface between a base material and a diamond layer. The diamond coated tool of the present invention is a diamond coated tool including a base material and a diamond layer coating a surface of the base material, and characterized in that the surface of the base material has an arithmetic average roughness Ra of not less than 0.1 &#x3bc;m and not more than 10 &#x3bc;m and an average length of roughness profile elements RSm of not less than 1 &#x3bc;m and not more than 100 &#x3bc;m, and that the diamond layer has a plurality of cavities extending from a portion bordering on the base material in a crystal growth direction.

A diamond electrode having a sufficiently low resistance is disclosed which is realized by increasing the amount of boron added thereto. A method for producing a high-performance, high-durability electrode is also disclosed by which adhesiveness between a diamond coating and a substrate and separation resistance during electrolysis are sufficiently increased. An electrode composed of a substrate and a diamond layer coating the substrate is characterized in that the electrode is composed of a base coated with diamond and the diamond contains boron in such an amount that the boron concentration is not less than 10,000 ppm but not more than 100,000 ppm. The base is preferably made of an insulating material.

Diamond-coated electrode and method for producing same

The invention offers a hard carbon film and a SAW substrate that are easy to fabricate or low in manufacturing cost while virtually maintaining the quality that affects the important properties of a device that comprises the hard carbon film or the SAW substrate. The hard carbon film comprises a composite film of graphite-like diamond and carbon clusters; the composite film has a continuous crystal structure.

Hard carbon film and surface-acoustic-wave substrate

This polishing apparatus permits for polishing of hard-material coated complex films that traditionally have been difficult to polish due to the hardness of the films, the fragility of the substrate, and the inherent distortion of the film. The polishing apparatus includes a rotary turn-table, a holder for a wafer having the film, a shaft connected to the center of the holder for transmitting rotation and pressure to the holder and permitting the holder to incline, an arm rotatably supporting the holder, a cylinder for applying pressure to the center of the shaft, a driving device for rotating the shaft, and at least one auxiliary shaft. The auxiliary shaft pushes peripheral points along a diameter of the holder in order to impart a swaying motion on the holder.

Polishing apparatus for polishing a hard material-coated wafer

Hard carbon film and surface acoustic-wave substrate

Surfaces of diamond crystals are examined by coating the surfaces with thin metal films, launching laser beams to the diamond surfaces in a slanting angle, detecting defects and particles on the diamond surfaces by the scattering of beams and counting the defects and particles by a laser scanning surface defect detection apparatus. Diamond SAW devices should be made on the diamond films or bulks with the defect density less than 300 particles cm . Preferably, the diamond,surfaces should have roughness less than Ra20 nm. Diamond SAW filters can be produced by depositing a piezoelectric film and making interdigital transducers on the low-defect density diamond crystals.

Diamond wafer, method of estimating a diamond wafer and diamond surface acoustic wave device

Surfaces of diamond crystals are examined by coating the surfaces with thin metal films, launching laser beams to the diamond surfaces in a slanting angle, detecting defects and particles on the diamond surfaces by the scattering of beams and counting the defects and particles by a laser scanning surface defect detection apparatus. Diamond SAW devices should be made on the diamond films or bulks with the defect density less than 300 particles cm,. Preferably, the diamond surfaces should have roughness less than Ra20 nm. Diamond SAW filters can be produced by depositing a piezoelectric film and making interdigital transducers on the low-defect density diamond crystals.

A method of producing and polishing a hard-material-coated wafer. A hard-material film is disposed on a substrate to form the wafer and provide the wafer with a convex shape. A surface of the substrate is fixed on a holder of a polishing machine having a whetstone turn-table. The holder is rotated about its axis, and the whetstone turn-table is revolved about its shaft. The convex film surface of the hard-material film is polished on the whetstone turn-table while the inclination angle of the holder relative to the turn-table is changed. In this way, the convex film surface is polished either from its center to its periphery or from its periphery to its center.

Method of polishing a hard material-coated wafer

A diamond wafer including a substrate and a (100) oriented polycrystalline diamond film grown on the substrate for making surface acoustic wave devices, semiconductor devices or abrasion-resistant discs. The (100) oriented film is produced by changing a hydrocarbon ratio in a material gas halfway from a higher value to a lower value. The wafer is monotonously distorted with a distortion height H satisfying 2 .mu.m.ltoreq..vertline.H.vertline..ltoreq.150 .mu.m. The film is polished to a roughness of less than Rmax50 nm and Ra20 nm.

Diamond wafer and method of producing a diamond wafer

No wide bulk diamond wafer exists at present. A wide diamond-coated wafer is proposed instead of the bulk diamond wafer. Diamond is heteroepitaxially deposited on a convex-distorted non-diamond single crystal substrate by a vapor phase deposition method. In an early step, a negative bias is applied to the substrate. In the case of a Si substrate, an intermediate layer of .beta.-SiC is first deposited on the Si substrate by supplying a low carbon concentration material gas. Then the carbon concentration is raised for making a diamond film. The convex-distorted wafer is stuck to a holder having a shaft which is capable of inclining to the holder. The wafer is pushed to a turn-table of a polishing machine. The convex diamond wafer can fully be polished by inclining the holder to the shaft. A wide distorted mirror wafer of diamond is produced. Fine wire patterns can be made on the diamond mirror wafer by the photolithography.

Growing community of inventors

Itami, Japan

Yuichiro Seki